参数资料
型号: LT1173CN8-5
厂商: Linear Technology
文件页数: 8/16页
文件大小: 0K
描述: IC REG BUCK BST INV 5V 0.4A 8DIP
标准包装: 50
类型: 降压(降压),升压(升压),反相
输出类型: 固定
输出数: 1
输出电压: 5V
输入电压: 2 V ~ 30 V
频率 - 开关: 23kHz
电流 - 输出: 400mA
同步整流器:
工作温度: 0°C ~ 70°C
安装类型: 通孔
封装/外壳: 8-DIP(0.300",7.62mm)
包装: 管件
供应商设备封装: 8-PDIP
LT1173
A PPLICATI
S I FOR ATIO
5 μ s/DIV
LT1173 ? TA07
5 μ s/DIV
LT1173 ? TA08
5 μ s/DIV
LT1173 ? TA09
Figure 2. Aluminum
Figure 3. Tantalum
Figure 4. OS-CON
In very low power applications where every microampere
is important, leakage current of the capacitor must be
considered. The OS-CON units do have leakage current in
the 5 μ A to 10 μ A range. If the load is also in the microam-
pere range, a leaky capacitor will noticeably decrease
efficiency. In this type application tantalum capacitors are
the best choice, with typical leakage currents in the 1 μ A to
5 μ A range.
Diode Selection
Step-Up (Boost Mode) Operation
A step-up DC-DC converter delivers an output voltage
higher than the input voltage. Step-up converters are not
short circuit protected since there is a DC path from input
to output.
The usual step-up configuration for the LT1173 is shown
in Figure 5. The LT1173 first pulls SW1 low causing V IN –
V CESAT to appear across L1. A current then builds up in L1.
At the end of the switch ON time the current in L1 is 1 :
t ON
( )
Speed, forward drop, and leakage current are the three
main considerations in selecting a catch diode for LT1173
converters. General purpose rectifiers such as the 1N4001
are unsuitable for use in any switching regulator applica-
tion. Although they are rated at 1A, the switching time of
a 1N4001 is in the 10 μ s-50 μ s range. At best, efficiency will
be severely compromised when these diodes are used; at
worst, the circuit may not work at all. Most LT1173 circuits
will be well served by a 1N5818 Schottky diode. The
i PEAK =
V IN
V IN
L
R3*
I LIM V IN
SW1
LT1173 FB
L1
D1
R2
+
C1
13
V OUT
combination of 500mV forward drop at 1A current, fast
turn ON and turn OFF time, and 4 μ A to 10 μ A leakage
GND
SW2
R1
current fit nicely with LT1173 requirements. At peak
switch currents of 100mA or less, a 1N4148 signal diode
* = OPTIONAL
LT1173 ? TA10
may be used. This diode has leakage current in the 1nA-
5nA range at 25 ° C and lower cost than a 1N5818. (You can
also use them to get your circuit up and running, but
beware of destroying the diode at 1A switch currents.) In
situations where the load is intermittent and the LT1173 is
idling most of the time, battery life can sometimes be
extended by using a silicon diode such as the 1N4933,
which can handle 1A but has leakage current of less than
1 μ A. Efficiency will decrease somewhat compared to a
1N5818 while delivering power, but the lower idle current
may be more important.
8
Figure 5. Step-Up Mode Hookup.
Refer to Table 1 for Component Values
Immediately after switch turn off, the SW1 voltage pin
starts to rise because current cannot instantaneously stop
flowing in L1. When the voltage reaches V OUT + V D , the
inductor current flows through D1 into C1, increasing
V OUT . This action is repeated as needed by the LT1173 to
Note 1: This simple expression neglects the effect of switch and coil
resistance. This is taken into account in the “Inductor Selection” section.
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LT1173CN8-5#PBF 功能描述:IC REG BUCK BST INV 5V 0.4A 8DIP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON(1.45x1) 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2
LT1173CN8-5PBF 制造商:Linear Technology 功能描述:LT1173CN8-5PBF
LT1173CN8PBF 制造商:Linear Technology 功能描述:LT1173CN8PBF
LT1173CS8 功能描述:IC REG BUCK BOOST INV ADJ 8SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:升压(升压) 输出类型:可调式 输出数:1 输出电压:1.24 V ~ 30 V 输入电压:1.5 V ~ 12 V PWM 型:电流模式,混合 频率 - 开关:600kHz 电流 - 输出:500mA 同步整流器:无 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC(0.154",3.90mm 宽) 包装:带卷 (TR) 供应商设备封装:8-SOIC
LT1173CS8#PBF 功能描述:IC REG BUCK BOOST INV ADJ 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON(1.45x1) 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2